Another two men are been held by detectives hunting the killers of a man shot in bed.
Brian McGlynn (28) was killed at his home in Derry, Northern Ireland, in front of his girlfriend.
Police have now detained five men over the murder, which may be linked to the victim's work as a doorman in the city.
The latest arrests were made in Belfast and Derry last night.
All of the suspects were being questioned at a serious crime suite in Antrim.
Mr McGlynn, originally from Strabane, Co Tyrone, was shot dead in the Fountain Hill area of Derry early on Sunday morning, with speculation that paid hitmen were involved.
Two masked men burst into the bedroom and shot him several times. He died instantly.
With no suggestion of a sectarian motive, police are trying to establish why he was killed.
They confirmed Mr McGlynn had been involved in disputes at some night-spots where he worked.
Police are understood to be examining an incident last month in which Mr McGlynn removed a man from the Red Rooms nightclub where he worked.